Pediatric Annals

Burn Injuries in Children

Charles V Coren, MD

Abstract

Thermal injury is the second leading cause of accidental death in children. The morbidity associated with bums exceeds that of other injuries. Thermal injury produces the greatest stress on the child's metabolism, again in excess of that seen in all other injuries. Thermal trauma to the skin results in scarring which leads to decreased function of the underlying musculoskeletal system. It may cause distant organ dysfunction or result in cosmetic deformity or imperfection. The combination of the pain associated with the injury and the guilt which usually occurs in the parents leads to profound emotional stress for the entire family.

Of particular importance is the fact that approximately one third of bum injuries occur as a result of child abuse. The bum is often not the first act of abuse and close examination may reveal other signs of physical or psychological abuse.

EPIDEMIOLOGY

In 1982, 18% of all accidental deaths in children under the age of 5 years were due to bums. Within the home, thermal injury is the number one cause of accidental death in children between the ages of 1 and 15 years. There is a predilection for males in the 1 to 4 year age group of 2 to 1. ' The average age for thermal injury in children is 32 months. While death may occur from bums over less than 40% of body surface area (BSA), it is especially ominous in the age group under 3 years, where a mortality rate of 75% occurs for bums between 40% to 49% BSA and a mortality rate of 88% for bums larger than 40% BSA.2

CLASSIFICATION

Burns are classified according to the depth of the injury. The assessment is made by clinical observation, although diagnostic techniques such as ultrasound or fluorescent perfusion have been described. The first degree burn is dry and erythematous in appearance (Table 1). Initially it is painful, becoming pruritic as it heals. A common example of a first degree burn is sunburn. It leads to minimal damage of the upper layers of the epidermis alone. Healing occurs within 1 week as a result of increased malpighian cell replication.

Second degree bums are identified by the formation of blisters. With removal of the blisters the burn appears moist and erythematous, and develops a whitish layer of eschar over the subsequent hours to days. After the eschar separates, epithelializationfrom the edges as well as from dermal appendages occurs to cover the wound. The length of time required for separation is directly proportional to the depth of dermal involvement. Superficial dermal bums maintain the highly cellular and elastic papillary dermal properties which permit a cosmetically adequate result within 1 to 2 weeks. Permanent destruction of the melanocytes can lead to a decreased pigmentation of the skin, however. Deeper dermal burns leave noticeable scars which are hard, inelastic, uneven and discolored. Here, epithelialization frequently requires 2 to 4 weeks to occur. The healed skin is prone to breakdown even after minor trauma, since it is less pliable. If the bum occurs over joints, as in the hands, skin grafting is advisable.

Table

In addition to the more obvious physical scars, less obvious psychological scars develop. These are most commonly seen in four perspectives: 1) the child's physical imperfection; 2) the parents' actual or perceived guilt for inadequate provision of prevention; 3) the pretnorbid psychological disturbance of the child who becomes prone to a reinjury; and 4) long-term psychological and emotional problems of the abused child.

Psychiatric evaluation and treatment plays an essential part of the coordinated burn team approach and should be instituted at the onset of the…

Thermal injury is the second leading cause of accidental death in children. The morbidity associated with bums exceeds that of other injuries. Thermal injury produces the greatest stress on the child's metabolism, again in excess of that seen in all other injuries. Thermal trauma to the skin results in scarring which leads to decreased function of the underlying musculoskeletal system. It may cause distant organ dysfunction or result in cosmetic deformity or imperfection. The combination of the pain associated with the injury and the guilt which usually occurs in the parents leads to profound emotional stress for the entire family.

Of particular importance is the fact that approximately one third of bum injuries occur as a result of child abuse. The bum is often not the first act of abuse and close examination may reveal other signs of physical or psychological abuse.

EPIDEMIOLOGY

In 1982, 18% of all accidental deaths in children under the age of 5 years were due to bums. Within the home, thermal injury is the number one cause of accidental death in children between the ages of 1 and 15 years. There is a predilection for males in the 1 to 4 year age group of 2 to 1. ' The average age for thermal injury in children is 32 months. While death may occur from bums over less than 40% of body surface area (BSA), it is especially ominous in the age group under 3 years, where a mortality rate of 75% occurs for bums between 40% to 49% BSA and a mortality rate of 88% for bums larger than 40% BSA.2

CLASSIFICATION

Burns are classified according to the depth of the injury. The assessment is made by clinical observation, although diagnostic techniques such as ultrasound or fluorescent perfusion have been described. The first degree burn is dry and erythematous in appearance (Table 1). Initially it is painful, becoming pruritic as it heals. A common example of a first degree burn is sunburn. It leads to minimal damage of the upper layers of the epidermis alone. Healing occurs within 1 week as a result of increased malpighian cell replication.

Second degree bums are identified by the formation of blisters. With removal of the blisters the burn appears moist and erythematous, and develops a whitish layer of eschar over the subsequent hours to days. After the eschar separates, epithelializationfrom the edges as well as from dermal appendages occurs to cover the wound. The length of time required for separation is directly proportional to the depth of dermal involvement. Superficial dermal bums maintain the highly cellular and elastic papillary dermal properties which permit a cosmetically adequate result within 1 to 2 weeks. Permanent destruction of the melanocytes can lead to a decreased pigmentation of the skin, however. Deeper dermal burns leave noticeable scars which are hard, inelastic, uneven and discolored. Here, epithelialization frequently requires 2 to 4 weeks to occur. The healed skin is prone to breakdown even after minor trauma, since it is less pliable. If the bum occurs over joints, as in the hands, skin grafting is advisable.

Table

TABLE 1CLASSIFICATION OF BURN WOUNDS

TABLE 1

CLASSIFICATION OF BURN WOUNDS

Third degree, or full thickness bums cause a coagulation necrosis of all epidermal and dermal elements. The burned skin is avascular and after the pigmented cells have been wiped away, the skin appears yellow because of the remaining carotene in the skin. The wound is dry, waxy, and appears contracted due to the desiccation of the tissue. While the dermal nerve endings may be destroyed in the bum area, surrounding nerve fibers are intact and the child can, therefore, experience a great deal of pain. Thrombosed vessels may be apparent in the wound. The stages of healing involve eschar separation, development of a bed of granulation tissue, epithelialization from the edges only, and scar contraction. The final result is an uneven, hard fibrotic scar without epidermal elements or pigment. Early grafting is recommended to reduce functional loss and cosmetic deformity.

Burns are also divided into major and minor groups which allows one to determine the need for hospitalization. The most reliable indicator of the severity of the bum is the percentage of body surface area involved. This can be quantified by the use of the Lund and Browder chart3 in the child, which is preferable to the "rule of nines" used in the adult (Figure 1). The calculation of percentage BSA bum applies to second and third degree burns only; first degree burns are usually not included. The designation of minor burns is limited to burns such as scalds or flash fire bums, which involve less than 10% BSA if they are limited to first or second degree burns. Third degree bums are considered to be minor only if less than 2% BSA is involved. An easy method to estimate the percentage of body surface involved is based on the size of the child's palm, which is roughly 1% of the BSA at any age. Children with major burns should be hospitalized and, in the case of severe burns (more than 20% BSA), the child should be admitted or transferred to a burn center.

Table

TABLE 2PEDIATRIC BURNS INDICATIONS FOR HOSPfTALIZATION

TABLE 2

PEDIATRIC BURNS INDICATIONS FOR HOSPfTALIZATION

Certain additional circumstances suggest the need for initial hospitalization: bums incurred as the result of an explosion or circumstances in which other organ trauma may have occurred; bums in infants less than 2 years of age; burns in children with chronic metabolic or connective tissue disorders; bums which are selfinflicted or the result of child abuse; and burns involving hands, feet, face or perineum should be admitted. Children with electrical, chemical or inhalation injuries also warrant hospitalization (Table 2).

ETIOLOGY

The type of bum varies with age and circumstances. In toddlers the hot water scald is most common (80%). Toddlers will explore new heights and, therefore, can easily pull a pot of hot liquid onto their face, neck, arms, and chest. Liquids, fortunately, cool quickly and run off, minimizing the time of contact. The resulting bum is scalloped in shape, develops blisters and incurs an uneven depth of injury, varying from an epidermal first degree to a deep dermal second degree injury (Figure 2). Hot grease and thick soup, which may not run off quickly, transmit more heat to the skin thus causing full thickness or third degree burns. Since the surrounding skin is not burned, grease burns can lead to the appearance of punched out lesions.

Figure 1. Modified Lund and Browder chart used on the Pediatrie Surgical Service at the Kings County Hospital for estimation of the bum surface area involved.

Figure 1. Modified Lund and Browder chart used on the Pediatrie Surgical Service at the Kings County Hospital for estimation of the bum surface area involved.

Figure 2. Eight-month-old male 3 days after he sustained a typical anterior chest scald burn by knocking a cup of tea out of his mothers hand. Therapy consisted of topical Silvadene® for 10 days.

Figure 2. Eight-month-old male 3 days after he sustained a typical anterior chest scald burn by knocking a cup of tea out of his mothers hand. Therapy consisted of topical Silvadene® for 10 days.

Figure 3. Six-month-old girl, 2 weeks after she sustained an 80%, third degree flame burn in a house fire. She died of sepsis Il¿ months after the injury

Figure 3. Six-month-old girl, 2 weeks after she sustained an 80%, third degree flame burn in a house fire. She died of sepsis Il¿ months after the injury

Non-hair bearing areas of the body have a greater susceptibility to thermal injury due to their thinner dermis. On the contrary, the thickened keratinized layers of palms and soles are protective, although they are frequent sites of potentially deep contact bums. Information concerning the relationship of the degree of temperature and duration of contact may help the clinician to evaluate the accuracy of the reported cause of the bum. Immersion into Kot water, for instance, will only result in a fiali thickness burn after an exposure of 10 seconds to at least 6O0C.4 Although some older buildings can still deliver hot water at this temperature, newer water heaters are set at 5O0C (12O0F), unlikely to cause third degree burns, except in neonates.

Flame burns follow scalds in frequency (15%). Although older children are most likely to sustain flame bums, the most severe injuries occur in infants unable to escape fires. The flame burn, like the scald, causes a coagulation necrosis but to a deeper level of the microvasculature of the skin. The appearance is yellowish-white with a dry waxy contrast. The burn wound is avascular and may show coagulated vessels coursing through the injury. While pin-prick sensation is absent, there is a great deal of pain in the surrounding area (Figure 3). Since any flame bum may be associated with inhalation injury, it should be ruled out or confirmed through physical examination and, if necessary, endoscopy. Full thickness injuries invariably require skin grafting.

Less common causes of burns include electrical, chemical, contact and firecracker injuries (5%), Electrical bums are of two .varieties: low and high voltage (> or <500V). The degree of tissue damage is related to the duration of exposure, the voltage of current, and resistance of tissues. Organs like the central nervous system and Heart are especially vulnerable to electrical injury, and if the current's pathway crosses the heart at a critical time in the cardiac cycle, lethal ventricular arrhythmias may result. Injury to the CNS may result in respiratory arrest from motor paralysis. Since resistance of skin is greater than muscle, myoglobinuria due to extensive muscle injury may occur without external appearance of a major injury. Moist skin has a far lower resistance to electric current, explaining its preferred entrance and exit. The current may arc across the moist antecubital, axillary, or popliteal spaces, generating sufficient heat to ignite clothing or cause a deep bum. The ocular lens has a great sensitivity to electrical injury which may result in cataract formation. The most common electrical injury in children results from chewing on an electrical cord (Figure 4). Although a low voltage injury, the lowered skin resistance and prolonged contact due to masseter muscle tetany can cause significant electrothermal injury to skin, mucous membrane, orbicularis muscle, and alveolar ridge. Bleeding from the labial artery usually occurs during the second week post-injury as the eschar begins to separate. The hemorrhage may be brisk enough to cause hypovolemia and for this reason, it is recommended to hospitalize these children throughout this period.

Figure 4. Two-year-old boy with a typical electrical cord burn to the corner of the mouth, prior to eschar separation. Final cosmetic and functional appearance of this injury was acceptable without surgical intervention.

Figure 4. Two-year-old boy with a typical electrical cord burn to the corner of the mouth, prior to eschar separation. Final cosmetic and functional appearance of this injury was acceptable without surgical intervention.

Figure 5. Four-year-old girl IO days after she sustained a third degree firecracker injury to the dorsum of the foot She required a nonmeshed split thickness skin graft after topical Silvadene* treatment.

Figure 5. Four-year-old girl IO days after she sustained a third degree firecracker injury to the dorsum of the foot She required a nonmeshed split thickness skin graft after topical Silvadene* treatment.

Tissue damage from chemical exposure varies in extent but is usually severe. Acid causes a coagulation necrosis; alkali causes a liquefaction necrosis, while other solvents penetrate the skin to injure the subcutaneous tissue and may become systemically absorbed. The initial care differs from the other causes of thermal injury only in that 20 to 30 minutes of continuous water irrigation should be used. Lye burns leave characteristic lines down from the area of initial contact. As the liquid runs along the skin, each area of contact leaves a deep penetrating burn. Most lye burns are full thickness and require skin grafting for their management. Chemical antagonists (antidotes) are not to be used since they may aggravate the injury.

Firecracker injuries are seasonal and usually affect three areas: the firecracker either explodes in the hand, is dropped on the foot, or may explode in the pocket, not infrequently shoved there by a friend. The jumping jack firecracker, the one most readily available to children, can cause full thickness injuries (Figure 5).

Contact burns can be caused by a variety of objects. Toddlers frequently touch hot irons (Figure 6) or radiators, while older children can burn their legs on the exhaust pipes of motor bikes. The doughnut shaped buttock burn in a child is likely to be caused by placing a child forcibly on a hot plate (Figure 7).

INITIAL TREATMENT

The initial evaluation should determine the nature of the burn, its extent, the degree of the bum and the presence of associated injuries.

Minor Burns

Minor bums can be adequately treated in an office or outpatient facility. Wound care consists of aseptic debridement, antiseptic cleansing and antimicrobial topical coverage. Blisters are a hallmark of a second degree burn and their early appearance is directly related to the depth of the bum. Certain areas with thickened keratinized skin, like the palm, form blisters which may maintain their integrity as opposed to areas on the ventral surface of the arm. Intact blisters are beneficial to healing by limiting tissue desiccation and pain. Once blisters are opened, they promote bacterial growth which may ultimately cause greater tissue destruction. All open blisters should be completely debrided, which is easy, since the superficial tissue can often be simply wiped away with moistened gauze. The wound is cleansed with either dilute povidone or other antiseptic solution and is thoroughly rinsed with saline or water. The wound is then dressed with a thin layer of silver sulfadiazine and protected with a bulky gauze bandage, separating digits with gauze. The same treatment is repeated by parents at home 'twice a day and the wound reexamined in the office every 3 to 5 days until healed. If eschar separation occurs early (3 to 5 days), one can assume the wound will be completely epi the Ii alized within 2 weeks. If eschar separation takes more than 1 week and granulation tissue develops in the base, the child should be considered for tertiary wound closure with skin grafting. If the child has a sulfa allergy, povidone ointment can be applied to the wound. Silver nitrate (0.5%) is also effective but it must be kept moist and it will stain virtually everything it penetrates. It also may cause hyponatremia and hypokalemia when applied to large areas. Mafenide acetate (10%) cream allows a deeper eschar penetration providing greater antimicrobial protection. It is painful, however, and in large quantities can produce a metabolic acidosis due to carbonic anhydrase inhibition. Neomycin-based ointments provide little antimicrobial protection. For the first few days the burn wound has considerable drainage which requires frequent dressing changes. Thereafter, daily dressing changes are adequate. Certain bums, such as burns of the ear, should be hospitalized and treated primarily with mafenide acetate to reduce the chance of developing chondritis. Systemic antibiotics are not indicated for the primary treatment of burns.

Parents should be warned from the outset that all second and third degree bums can leave permanent scars regardless of treatment.

Major Burns

The first priority of management of severe bums consists of cardiopulmonary resuscitation utilizing the ABCs of pediatrie trauma. The airway is secured, and supplemental oxygen administered if necessary. The burning process is stopped, the smoldering clothes are removed, chemical burns are copiously irrigated. Intravenous access is established with an isotonic fluid simultaneously in the field while the child is transported to an appropriate hospital. On admission a secondary survey of the child, looking for other injuries including those of child abuse, is performed. Further management of severe bums must include placing a nasogastric tube and a Foley catheter. The bums are evaluated for degree and extent, then cleansed, debtided and dressed, with adequate intravenous sedation. Tetanus prophylaxis is administered and, finally, the child is admitted to an intensive care room with an ambient temperature that prevents shivering. The size of the burn indicates the need and amount of IV fluids. For bums between 10% to 20% BSA the child can take some or all fluids orally. Above 20% a gastric ileus may develop and an IV resuscitation and nasogastric drainage are needed. The subject of fluid resuscitation has received close attention and various formulae have been developed which are based on extensive clinical and laboratory research.2·5 The basis for the fluid administration dates back some 40 years. Regardless of the formula used, there are several common themes to all of these approaches: staying ahead of deficits and maintaining normal vascular pressures will reduce tissue hypoxia in the area of an injury as well as in distant organs. The resuscitation should therefore begin as soon after the injury as possible. The greatest shift of fluid and electrolytes occurs within the first 8 hours. Urinary output remains one of the standards to evaluate the adequacy of the resuscitation formula. An adequate urinary output is considered to be 0. 5 mlAg/ hour, provided the urinary osmolality and specific gravity is within normal range. An infant's output of twice the volume (1.0 mL/kg/hour) is necessary. The urinary output is correlated with pulse rate, pressure, capillary refill and sensorium (Table 3). The volume of the resuscitory fluid is based on weight or surface area. The former, known as the Parkland formula, administers Ringer's lactate at 4.0 mL/kg/% BSA burned for the first 24 hours. One half is administered in the first 8 hours, the second half in the subsequent 16 hours. Carvajal has suggested a formula based on surface area: 5000 mL/m2 BSA burned plus 2000 mL/m2 maintenance, again one half administered in the first 8 hours.6 This formula appears to be most appropriate for the smaller infants and those with larger bums (Table 4). Details of the fluid to be used, such as added colloid or hypertonic fluids, are not dealt with here; their use is controversial and should be agreed upon and precisely calculated by all members of the burn team prior to their administration. The controversy over use of colloid in burn shock resuscitation concerns the development of pulmonary edema from "leaky" capillary membranes. Clinical and laboratory study of pulmonary hemodynamics demonstrates that increased lung lymph flow compensates for the increased hydrostatic pressures, and pulmonary edema does not occur until sepsis develops. 7 As soon as the shock phase is over a transition from intravenous to oral fluids is accomplished. The establishment of early enterai nutrition is the best hope for prevention of sepsis, the main cause of death in burned children after the initial resuscitory phase. The use of prophylactic penicillin is reserved for children with documented streptococcal infections.

Figure 6. Three-year-old boy 1 week after he sustained a hot iron contact burn to the hand. This hand had received 1 week therapy with topical Silvadene® treatment and required a nonmeshed skin graft.

Figure 6. Three-year-old boy 1 week after he sustained a hot iron contact burn to the hand. This hand had received 1 week therapy with topical Silvadene® treatment and required a nonmeshed skin graft.

Figure 7. One-year-old boy 1 day after an alleged fall against a radiator. Final investigation revealed that the child was held intentionally against the radiator, leading to a contact burn frequently seen in abused children.

Figure 7. One-year-old boy 1 day after an alleged fall against a radiator. Final investigation revealed that the child was held intentionally against the radiator, leading to a contact burn frequently seen in abused children.

Table

TABLE 3PARAMETERS OF ADEQUATE TISSUE PERFUSION

TABLE 3

PARAMETERS OF ADEQUATE TISSUE PERFUSION

OPERATIVE THERAPY

The two objectives of operative therapy are removal of necrotic or infected tissue and the coverage of wounds. The first is used to control or diminish wound sepsis after failed local wound care and topical therapy. At some institutions early excision of the bum within 3 to 5 days is the preferred treatment not only for severe burns, but also for those frequently associated with functional loss. Skin coverage can either be provided early at the time of excision or 1 to 2 weeks later, when the area has a healthy bed of granulation tissue. Nonmeshed grafts are utilized in mobile areas such as the hand and cosmetic areas such as the face. Meshed grafts, 1.5 to lor 3 to 1, are used when large burn areas have to be covered. Temporary coverage with pigskin or synthetic material is employed after separation of the eschar in the superficial burns, or after excisional therapy in the deeper burn in preparation for grafting.

The operative management requires a coordinated approach by a team familiar with pediatrie bum critical care. Particular attention is needed to maintain thermal neutrality and replace operative blood loss. It is preferable to perform multiple staged procedures than to excise or graft large burn surface areas at one time.

LONG-TERM MANAGEMENT

Following epithelialization of the wound or complete healing of the graft, a fitted elastic garment (eg, Jobst®) may have to be worn continuously for 1 year. In a growing child these garments may need to be refitted, depending on the rate of growth. The time interval between burn and graft or healing appears to be proportional to the degree of skin contracture which may occur. This finding has been correlated h isto logically with the appearance of myofibroblasts in the wound. Since all burns may exhibit some degree of contracture, long-term results cannot be reliably predicted. Early institution of rehabilitation, preferably from day 1 of treatment to long after the patient is discharged, can alleviate a considerable degree of functional deformity caused by burns. Hypertrophie scars can be expected; they are part of the healing process of deep burns. They are initially treated with elastic garments but may require excision later with or without the use of tissue expanders. Finally, the mere loss of normal pigmentation alone can cause great emotional distress, especially when a bum occurs over the face or hands. At the present time, the only available treatment for depigmentation is the use of custom prepared makeup.

Table

TABLE 4PEDIATRIC BURNS INTRAVENOUS FLUID THERAPY FIRST 24 HOURS

TABLE 4

PEDIATRIC BURNS INTRAVENOUS FLUID THERAPY FIRST 24 HOURS

In addition to the more obvious physical scars, less obvious psychological scars develop. These are most commonly seen in four perspectives: 1) the child's physical imperfection; 2) the parents' actual or perceived guilt for inadequate provision of prevention; 3) the pretnorbid psychological disturbance of the child who becomes prone to a reinjury; and 4) long-term psychological and emotional problems of the abused child.

Psychiatric evaluation and treatment plays an essential part of the coordinated burn team approach and should be instituted at the onset of the injury.8 Sociological investigation of the child, the family, its socioeconomic background, and each family's particular circumstances and needs may help to prevent recurrent injuries not only to the involved child, but also to other family members.

REFERENCES

1. Accident Facts, Nacional Safety Council. Chicago. 1983.

2. Hemdon DN. Thompson PB, Desai MH, et al: Treatment of bums in children. Pediatr Clin North Am 1965; 32(5)-1311-1332.

3. Lund CC, Browder ND: The etcimation of areas of bums. Surg Gvnecol Obitet 1944; 78:463.

4. Mortiz AR, Hendriquez FC: The relative importance of time and surface temperature in the causation of cutaneous bums. Am J Pathol 1947; 23:625-720.

5. Demling RHi Bums. N Engl J Med 19T5; 313(22):1389-1398.

6. Carvajal HF: A physiologic approach to fluid therapy in severely burned children. Surg Gynecol Obsta 1980; 150:379- 384.

7. Tranbaugh RF, Elings VB. Chrisienson JM. et ali Effect of inhalation injury on lung water accumulation. J Trauma 1983; 23:597-604

8. Libber SM, Stayton DJ: Childhood hums revisited: The child, the ramily, and the bum injury. J Trauma 1984; 24(3):245-252.

TABLE 1

CLASSIFICATION OF BURN WOUNDS

TABLE 2

PEDIATRIC BURNS INDICATIONS FOR HOSPfTALIZATION

TABLE 3

PARAMETERS OF ADEQUATE TISSUE PERFUSION

TABLE 4

PEDIATRIC BURNS INTRAVENOUS FLUID THERAPY FIRST 24 HOURS

10.3928/0090-4481-19870401-08

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